Addictions, both substance and behavioral, have been conceptualized as having common biopsychosocial processes with different opportunistic expressions (Shaffer et al., 2004). Traditionally, substance use disorders have received significant attention in the literature due to presumed inherently addictive nature of the substance. In contrast, research has focused much less on behaviorally based addictions, such as gambling. Biological processes such as the hormonal response to stress, measured by cortisol, dehydroepiandrosterone (DHEA), and the ratio of the cortisol/DHEA, may underlie the disposition to develop an addictive disorder, regardless of whether it is a substance-based or a so-called behavioral addiction. The proposed study will be conducted with heavy smokers, problem scratch-off gamblers, and healthy controls to investigate the effect of an acute social stressor on reactivity to smoking or gambling cues. Subjective (urges, cravings) and physiological responses (skin conductance and heart rate) will be measured in response to smoking or gambling cues versus neutral cues, once under normal conditions and again after exposure a social stressor. Stress hormones (salivary cortisol and DHEA) will be measured repeatedly during the procedures. It is hypothesized that cigarette smokers and problem gamblers will display a similar cortisol response to the acute stressor in comparison to the control group. In addition, heavy smokers and problem gamblers will display similarly blunted cortisol responses to an acute stressor. In addition, cue reactivity in smokers and gamblers will increase following a stressor compared to non-stressed cue exposure. Finally, it is hypothesized that a higher baseline cortisol/DHEA ratio will predict higher subjective and physiological arousal to active cues and be associated with increased symptoms and more adverse consequences of addiction.